Motion converting mechanism



Feb. 9, 1965 c. a. SMITHSON 3,168,834

MOTION CONVERTING MECHANISM 5 Sheets-Sheet 1 Filed Aug. 29, 1962INVENTOR.

B C/zazksBSWow 4 (W/g Feb. 9, 1965 c. B. SMITHSON 3,168,834

MOTION CONVERTING MECHANISM Filed Aug. 29, 1962 5 Sheets-Sheet 2INVENTOR. C/zarlesflSmzfiwom I I 3 I I a United States Patent 3,168,834MOTION CONVERTING MEiIHANISM Charles B. Smithson, 33 Country Club Place,Eloomington, Ill. Filed Aug. 29, 1952, Ser. No. 220,238 20 Claims. (Cl.74-23) This invention relates to improvements in power driven devicesgenerally and more particularly to an improved power driven tool or handimplement such as a toothbrush. More specifically, the invention relatesto a novel and improved motion converting means for use in a powerdriven device.

Various mechanisms have been suggested for power driven toothbrusheswhereby the rotary motion of a motor shaft is converted to some type ofreciprocating, oscillatory, or orbital motion at the brush or workingend of the device. However, the devices heretofore known have hadcertain disadvantages which have restricted their commercial developmentand exploitation. For example, the previously known devices have beenlimited in power output or have been excessive in size in manyinstances. Furthermore, the motion converting or translating mechanismof such devices has usually been limited with respect to the type ofoutput motion which can be obtained. In addition, in many instances ithas been necessary to mount the motor with its drive shaft extendingtransversely of the longitudinal axis of the casing in order to obtain adesired type of motion at the working end of the device.

The present invention is designed to overcome the foregoingdisadvantages ;by means of a novel and improved motion converting ortranslating mechanism.

Accordingly, a primary object of the invention is to provide a novel andimproved motionconverting mechanism for a power driven device,particularly a hand tool or implement.

Another object of the invention is to provide a novel and improvedmotion converting mechanism for a power driven device which is capableof providing a variety of desired motions at the working end of thedevice.

A further object of the invention is to provide an improved power drivendevice having a novel and improved motion converting mechanismcharacterized by a powerful but compact structure such that themechanism is particularly useful in a power driven hand tool orimplement.

An additional object of the invention is to provide a novel and improvedmotor driven device wherein the motor is mounted with its drive shaftextending longitudinally of the device and a motion translatingmechanism is provided which is capable of converting rotary motion ofthe drive shaft to a predetermined type of straight line, oscillatory,or orbital motion, or combinations thereof, at the working end of thetool.

Other objects and advantages of the invention will become apparent fromthe subsequent detailed description taken in conjunction withtheaccompanying drawings, wherein:

FIG. 1 is a reduced scale side elevational view of a power driventoothbrush constituting one specific embodiment of the invention;

FIG. 2 is an enlarged vertical sectional view at the forward end portionof the tooth brush illustrated in FIG. 1;

FIG. 3 is a transverse sectional View taken along the line 3-3 of FIG.2;

FIG. 4 is a plan view of the interior of the toothbrush with the upperhalf of the casing removed and. the gear mechanism revolved 90 from theFIG. 2position;

FIG. 5 is a transverse sectional view taken along the line 5-5 of FIG.4;

FIG. 6 is a schematic view illustrating the different positions of themechanism shown inFIGS. 2 and 5;

FIG. 7 is a vertical sectional view similar to FIG. 2 but showing amodified form of the invention;

FIG. 8 is a plan view of the interior of the structure shown in FIG. 7with the upper half of the casing removed and the gear mechanismrevolved from the FIG. 7 position;

FIG. 9 is a vertical sectional view similar to FIGS. 2 and 7 but showinganother embodiment of the invention;

FIG. 10 is a transverse sectional view taken along the line Iii- 11i) ofFIG. 9 with the gearmechanism revolved 90 from the FIG. 9 position;

FIG. 11 is a transverse sectional view taken along the line 11-11 ofFIG. 9;

FIG. 12 is a vertical sectional view similar to FIGS. 2 7 and 9 butshowing still another embodiment of the invention;

FIG. 13 is a transverse sectional view taken along the line 13-13 ofFIG. 12 with the gear mechanism revolved 90 from the FIG. 12position;

FIG. '14 is a vertical sectional view similar to FIGS. 2, 7, 9, and 12but showing still another embodiment of the invention; FIG. 15 is atransverse sectional view taken along the line Iii-d5 of FIG. 14 withthe gear mechanism revolved 90 from the FIG. 14 position;

FIG. 16 is a horizontal sectional view taken along the line 16-1( ofFIG. 14 but with the mechanism in a different position;

FIG. 17 is a transverse sectional view taken along the line 17-JL7 ofFIG. 14; and

FIG. 18 is a fragmentary vertical sectional view taken substantiallyalong the line 18-18 of FIG. 16.

In FIGS. 1-6, one specific embodiment of the invention is illustratedcomprising, in this instance, a power driven toothbrush. Although, forthe sake of convenience, the

invention is hereinafter described in connection with a toothbrush, itis to be understood that the principles of the invention, including thenovel motion converting mechanism, may also :be used for other typesofpower driven devices, particularly tools and implements such as a saw,file, polisher, sander, etc.

As seen in FIG. 1, the toothbrush comprises an elongated housing orcasing 2-0 of suitable plastic or other nonconductive material, thecasing having detachable upper and lower halves 21 and 22, respectively,which are held together by screws 25. An electric power cord 23 extendsfrom a reducedportion 24 at the rear end of the casing 29, and adetachable toothbrush 26 having a shank portion 27 and a brush portion28 is mounted at the forward or nose end of the casing 20. A hand switch2? projects from one side of the casing 20 for starting and stopping thedrive of the toothbrush. Instead of electric power from the cord 23, itwill be understood that the casing 21) could be provided with aself-contained power supply such as a battery or the like.

Referring to FIGS. 2-5, an elongated cylindrical motor 31 is mountedwithin the casing 20' with its drive shaft 32 (FIG. 2) extendinglongitudinally or axially of the casing 20. The rotary motion of themotor drive shaft 32 is converted to a predetermined desired type ofmotion at the brush 28 by means of a motion converting or translatingmechanism indicated generally at 33 and comprising the principal novelfeature of the present invention. 36 are driven in opposite directionsby means of a pinion 37 mounted on the motor shaft 32. The gears 34 and36 are provided with hub portions 38 and 39, respectively, which arejournaled in a pair of upper and lower brackets 41 and 42, respectively.The brackets 41 and 42 are rigidly secured to the motor 31 andextendforwardly therefrom in transversely spaced relation, as best seenin FIG. 2. The brackets 41 and 42 are provided A pair of spaced coaxialbevel gears 34 and v.3 with beveler openings 43 and 44, respectively,with a plurality of radial ball bearings 46 and 47 being disposed in therespective openings for journaling the hub portions 38 and 39 of thegears and retaining the latter in driving relation :with the pinion 37.

The power take-off from the gears 34- and 36 i provided by means of aresilient yoke 48 of spring metal or the like having a pair of upper andlower arms 49 and 51, respectively, which are interconnected by alaterally enlarged central bight portion 52:. The outer axial ends ofthe gear hubs 38 and 39 are provided with restricted sockets 53 and 54,respectively, and the outermost end portions of the yoke arms 49 and 51are provided with restricted apertures 56 and 57, respectively, toaccommodate a pair of balls 58 and- 59 therebetween. As best seen inFIG. 2, the sockets 53 and 54 are disposed to one side of or ineccentric relation to the axis.

of rotation of the ring gears 34 and 36. The spring pressure exerted bythe resilient yoke 48 holds the balls 53 and 59 in driving relationbetween the gear hubs 38, 39 and the corresponding yoke arms 49, 51.rality of ball bearing elements 61 are in rolling engagement between theopposed inner faces of the gears .34 and 36 for receiving the axialthrust of the gears.

As hereinatfer described in more detail, the rotary motion of the pinion37 on the motor drive shaft is converted by the motion converting means33 to a combined reciprocating and rocking movement of the yoke 43. Thiscombined motion of the yoke 4-8 is transmitted to an outer socket member62 having a cylindrical side wall 63, an inner axial end wall 64abutting the yoke center portion *52, and an outwardly extending flange66 at the open end of the socket. In this embodiment, a loose swivelconnection is provided between the yoke center portion 5.2 and thesocket end wall 64 by means of a shoulder screw 67 extending through anenlarged unthreaded opening 68 in the end wall 64 and engaged in athreaded opening 69 in the yoke portion 52. As will be evident from FIG.2, the aligned openings 6-8 and 69 are off-center or eccentric withrespect to the center line of the motor shaft 32 and the yoke '48. For apurpose to be described hereinafter, the socket end wall 64 and the yokeportion 52 are also provided with an enlarged unthreaded opening 71 anda smaller threaded opening 72,

respectively, which are coaxial with the drive shaft 32 and thecenterline of the yoke 48.

The outer socket member 62 has a shiftable fulcrum arrangement so as topermit both straight line reciprocating movement of the socket 62 andalso side-to-side pivotal movement; Thus, the 'forward or nose end ofthe casing 20 has' an enlarged end opening 73 through which the outersocket 62 extends with an annular clearance space 74 (FIG. 3)therebetween. The cylindrical wall 63 of the outer socket 62 is providedwith a pair of opposed axially extending grooves 76, and acooperatingpair of grooves 77 are provided in the housing opening 73. A pair ofrollable ball elements 78 are interposed between the two sets ofgrooves. Accordingly, the outer socket member 62 which is connected tothe yoke 48 can move back and forth in-a longitudinal direction and atthe same time the socket 62 can pivot from side to side about the balls78 as a movable fulcrum within the confines of the annular clearance 74.

For detachably receiving the shank 27 of the toothbrush 26, an innercylindrical socket member '81 of plastic or the like is detachablysecured within the outer socket member 62 by means of a bayonet slotconstruction 82 having an; interlocking relation with the inwardlydepressed portions of the outer socket wall 63 which define the grooves76. A flexible seal or boot 83 of rubber or other suitable materialencloses the forward or nose end oi the casing 2tl and issecured to thelatter by means of an annular hangefor head portion 84 which is seatedsnugly in a circumferential groove 86 encircling the nose end of thecasing. The opposite end of the seal 83 is A plu- Y clamped between thefiange 66 of the outer socket 62 and a flange 87 on the inner socketmember 8 1 by means of a hat washer 88 and a resilient spring wavewasher 89. The spring action of the resilient washer 89 also serves toretain the inner socket member 81 in engaged relation within the outersocket member 62 While at the same time permitting the two socketmembers to be disconnected by pressing the socket member '81 axiallyinwardly and rotating the same to disengage the bayonet slot connection32. Upon withdrawal of the inner socket member 81, the shoulder screw 67becomes accessible for the purpose hereinafter described. The innersocket member 81 is provided with a square opening 91 for receiving thecorrespondingly shaped shank 27 of the toothbrush 26, the shank 27 beingreleasably retained in the socket member 61 by means of a plurality ofdepressible detents 92 on the shank 27 which are engageable withcooperating recesses 93 at the inner walls of the socket member 81.

To understand the motion of the yoke 48 of the motion convertingmechanism 33, it is helpful to consider an imaginary filament or linestretched between the centers of the powertake-oifball elements 58 and59. As the gears 34 and 36 rotate inopposite directions, the powertake-off balls 58 and 591are driven in opposite circular paths so thatthe imaginary line undergoes a compound movement including aback-and-forth reciprocating motion longitudinally of thecasing 20 andalso an oscillating or rocking movement transversely of the casing 20about the axial center line of the motor shaft 32 as a pivot center.However, regardless of the longitudinal displacement of the imaginaryline or its transverse inclination, the imaginary line is alwaysperpendicular to the axial center line through the motor shaft 32. g

In FIG. 2, the power take-off balls 58 and 59 are shown in their extremeforward position wherein the power take-off balls are disposedvertically one above the other so that the yoke 48 is displacedforwardiy the maximum distance of its stroke. This condition of thepower take-oil is illustrated schematically in FIG. 6 by the position Aof the imaginary line, extending between the power take-off balls. Asthe gears 34 and 36 rotate from the FIG. 2 position to the positionshown in FIGS. 4 and 5, the imaginary line between the power take-offballs 58 and 59 is retracted rearwardly in the casing onehalf of itsmaximum displacement distance and at the same time the imaginary line isinclined in a transverse plane to the position indicated at B in theschematic view of FIG. 6. As the gears 34 and 36 rotate-another 90, theballs 58 and 59 and the imaginary line therebetween again assume avertical position but are now disposed at their extreme rearwardmostposition, as indicated schematically at C in FIG. 6. Continued rotationof the gears 34 and 36 through another to complete a single revolutionwill cause the imaginary line between the balls 58 and 59 to passthrough an oppositely inclined ends thereof will trace an ellipse whosemajor axis has the same dimension as the diameter of'the circles tracedby the ends of the line and whose minor axis depends on the distance ofthe point in question from the axial center" line of the motor shaft.Consequently, when'the yoke v4-8 of the motion converting mechanism 33has a loosepivotal connection with the socket member62 by means, of

the shoulder screw'67 andthe aligned oil-center holes 68 and 69, asshown in FIG. 2, it will beunderstood thatthe motion of the yoke 48- isbeing transmitted to the socket member 62 at an ellipse-generating pointbetween the center and the upper end extremity of the imaginary linebetween the power takeoff balls 58 and 59.

As seen schematically in FIG. 6, the solid line position of theconnecting shoulder screw 67 is substantially midway between the centerof the imaginary line and the upper extremity defined by the powertake-01f ball 58. Thus, the power take-01f point 67 from the yoke 48generates an ellipse, as illustrated at the bottom of FIG. 6, whosemajor axis is the same as the distance between the lines A and C andWhose minor axis is the same as the maximum displacement distance of thetake-off point 67 in the oppositely inclined positions of the lines Band D. Because of the loose pivotal connection between the yoke 48 andthe socket member 62 and because the socket member 62 is restrained fromrotating about its central longitudinal axis by reason of the coactionbetween the fulcrum balls 78 and their grooves 76 and 77, the ellipticalmotion generated at the inner end of the socket 62 is substantiallyreproduced at the brush 28. However, the dimensions of the minor axis ofthe ellipse will be altered depending upon the relative distancesbetween the shifteble fulcrum and the opposite ends of the movingmechanism comprising the socket wall 64 and the brush 28. By properlyproportioning these distances, it is possible to obtain at the brush amotion that is substantially elliptical or substantially circular,either of which paths may be described generically as orbital or ashaving both longitudinal and lateral components.

Referring to FIGS. 1 and 2, substantially circular motion of the brush28 or other tool will result if the ratio ezE is the same as the ratiof:F, where e is the distance from the axial center line of the motorshaft 32 to the center of the shoulder screw 67, E is the distance fromthe same center line to the center of the eccentric power take-01f ball58 or 59, f is the distance from the axis of rotation of the gears 34and 36 to the movable fulcrum point 78, and F is the distance from thetool point or brush 28 to the same movable fulcrum 78'. If the ratiose:E and fzF are differenna substantially elliptical or non circularorbital motion will be obtained.

It will also be understood that if the shoulder screw 67 is installedthrough the aligned openings 71 and 72 which are on the center line ofthe motor shaft 32, the lateral component of movement of the yoke 48 iscompletely canceled out and the brush 2.8 undergoes straight linereciprocating movement longitudinally of the casing 20. This conditionis also shown schematically in FIG. 6 at the dotted line position of thescrew 67 from which it will be seen that the maximum reciprocatingdistance comprises the distance between the lines A and C, but in atransverse plane the movement of the imaginary line be tween positions Band D causes no lateral displacement of the power take-off point 67.Thus, by locating the shoulder screw 67 in the desired set of holes andby properly proportioning the lengths of the pivot arms extending inopposite directions from the shiftable fulcrum 78, it is possible toobtain in a single tool either straight line reciprocating movement orany desired type of orbital movement, including circular and ellipticalpaths.

Because of the square configuration of the socket opening 91 and thecorresponding configuration of the tool brush shank27, it is possible byproperly orienting the brush handle in the socket to take advantage oforbital motion of the brush in several different ways without changingthe position of the casing 2t). This characteristic may have particularimportance in the case of certain types of tools or implements otherthan a toothbrush. For example, with the device in the position shown inFIG. 1, the orbital motion at the brush 28 can be used for full orcontinuous contact polishing, sanding, or cleaning of a top surface orthe like. By reversing the position of the brush member 180 so that thebrush portion or other tool point extends upwardly instead ofdownwardly, the same type of continuous or full con- 6 tact may beobtained for working on the underside of a surface or the like. In thecase of a different type of tool or implement, such as a saw blade orfile, the square shank of the tool can be oriented in the inner socket81 so that the orbital motion is imparted to the tool point in avertical plane instead of in a horizontal plane as in FIG. 1. Thus, thetool point will have a rolling or stroking motion relative to the workwhich would provide for automatic cleaning on the return stroke in thecase of a saw blade or file.

It will also be evident that with the motion converting mechanism 33,still other modifications may be realized to obtain additional types ofoutput motions. For example in FIG. 2 the outer socket 62 may berotatably supported in the casing opening 73 by suitable annular bearingmeans and may also be rigidly connected to the yoke portion 52 with thelongitudinal axis of the socket in coaxial relation with the motor shaft32. With this modification, it will readily be understood that thesocket member 62 will undergo straight back and forth reciprocatingmovement combined with oscillating rotary movement about itslongitudinal axis. This motion is particularly useful for chip clearanceand removal in a drilltype boring tool.

The use of a pair of opposed gears 34 and 36 in the manner described hasspecial advantage in the case of relatively small hand tools orimplements because of the compactness of the design which at the sametime permits the motor 31 to be mounted in longitudinal relation in thecasing 20. Inasmuch as only one-half the total power output is beingtaken from each gear, the gears can be made substantially smaller thanwould otherwise be the case thereby realizing a compact constructionwith out sacrificing power output.

FIGS. 7 and 8 illustrate a modification of the motion convertingmechanism 33 heretofore described. Those portions of the structure whichare essentially the same as in FIGS. 1 to 5 are. identified by the samereference numerals in FIGS. 7 and 8. In this modification the upper gear34 of the first embodiment has been eliminated and in place thereof abracket 96 has beensubstituted, the bracket having a horizontal portion97 extending rigidly from the end of the motor 31 and being pro vided atits underside with a suitable raceway for the thrust ball elements 61.The spring yoke member in this instance is designated generally at 93and has a lower arm 99 and a central portion 161 which are essentiallythe same as the arm 51 and the portion 52 in the first describedembodiment. The lower arm 99 has a restricted opening 102 for receivingthe power take-off ball 59 in the manner previously described. Thecentral portion 101 of the yoke 98 has the same connection with theouter socket member 62 which need not be described in further detail.

At the upper end of the yoke 98 a horizontal arm portron 103 is disposedadjacent the bracket portion 97 and is integrally connected to thecentral yoke section 101 by means of an inverted U-shaped connectingportion 104. The bracket portion 97 and the opposedyoke arm 163 areprovided with confronting grooves 106 and 167, respectively, and a ballbearing element 103 is disposed therebetween. The groove 1061's arrangedparallel to the axial center eccentric power take-off ball 59 undergoescircular movement during rotation of the ring gear 36, the ball bearingelement 168 supports the yoke arm 103 for back-andforth reciprocatingmovement while at the same time accommodating transverse rocking orswivel movement of the yoke arm 193 about the ball element 108 Thus,with the use of only a single gear 36 driven by the pinion 37, the sameselective straight line or orbital movement may be obtained from themotion converting mechanism. However, in this case the shoulder screwopenings 68 and 69 are aligned axially with the center line of the pathof line of the motor shaft 32 so that as the areassa reciprocatingmovement of the ball 1118 and with the shoulder screw 67 in theseopenings the socket 62 undergoes straight reciprocating movement. Whenthe openings 71 and 72 are utilized, orbital motion is obtained.

F168. 9 to 11 illustrate another embodiment of the invention utilizing adiiierent socket fulcrum arrangement and a'dififerent power take-oilmeans from the rotating gear. The casing comprises two sections 111 and112 housing a motor 113 which drives a pinion gear 114. A pair of bevelgears 115 and 117 of plastic or the like have integral hub portions 118and 119, respectively, which are journaled in tubular bosses 121 and122, respectively, projecting from the wall of the casing. The gears 116and 117 are driven in opposite directions by the pinion 114.

A pair of metal swivel balls 123 and 124 are rotatably mounted incorresponding sockets in the gears 116 and 117 in eccentric relationwith respect to the axis of rotation of the gears and projectingslightly from the opposed faces of the gears. The balls may be molded inplace during fabrication of the plastic gears and thereafter may bebroken free of the plastic material. The sockets are then suitablylubricated to permit free swivel movement of the balls. The halls 123and 124 are interconnected by means of a shaft segment or pin 126 whichperforms the essential function of the yoke 48 or 98 in the previouslydescribed embodiments of the invention. The opposite ends of the pin 126are slidable in suitable bores in the balls 123 and 124 to accommodaterotation of the gears. An intermediate swivel ball element 127' isaxially bored and is slidably andadjustably mounted on the pin 126intermediate the end ball elements 123 and 124. The swivel ball element127 is also rotatably retained in swivel relation in a complementarysocket portion formed at the inner end extension 128 of a plastic socketmember 129 having a square or non-circular external cross-section. Thesocket member 129 is also provided with an inner opening 131 of squarecross-section for detachably receiving the toothbrush shank 27 or othertool in the same manner as heretofore described. The outermost end ofthe socket member 129 has a circumferentially grooved flange portion 132for receiving the beaded end 133 of a flexible rubber seal 134. Theopposite end 136 of the seal 134 is retained in a groove 137 at the endof the casing. Asbefore, the function of the seal 134 is to enclose anenlarged opening 135 at the forward end of the casing and through whichthe socket member 129 extends.

In this instance, the fulcrum for the socket member 129 comprises asquare tubular section 138 having the square socket member 129 slidablydisposed therein but restrained against rotation about its longitudinalaxis. The fulcrum member 138 has oppositely extending integral shaftextensions or pin portions'139 and 141 which are rotatably journaled inand axially shit-table in a pair of tubular bearing bosses 1 12 and 143,respectively, extending inwardly from the casing. A coil spring 14-4 isinterposed between one side of the fulcrum member 138 and the casingsection 111 for urging the fulcrum member 138 toward the opposite casingsection 112. An adjusting screw 146 is threaded into the tubular bearingboss 143 and has an enlarged head portion 147 disposed at the exteriorof the casing for manipulating the same. The inner end of the screw 146abuts the pivot pin 141 of the fulcrum member 138. By reason of theslid-able relationship between the swivel ball 127 and the shaft segmenti 126, it will be seen that the position of the swivel ball element 127relative to the rotating ball elements 123 and 124 can readily beadjusted by means of the screw 146 which regulates the transverseposition of the vfulcrum member 138.

By adjustment of the position of the swivel ball element 127, it will beunderstood that the power take-off point for the socket member 129 iscorrespondingly adjusted halves 151 and 152 which contain a motor153having a plane therethrough.

thereby determining the straight line or orbital character of the pathof movement transmitted to the brush or other tool. axial center line ofthe motor shaft, the socket member 129 will undergo a simpleback-anddorth straight line reciprocating movement. However, when theswivel ball element 127 is located in a position intermediate the motorshafit center line and one of the balls 123 or 124,

an orbital movement is transmitted to the brush which may be eithercircular or elliptical dependent upon the proportioning factorsheretofore discussed. It will also be understood that if the ball 127 islocated between the center line of the motor shaft and the ball element123, the path of orbital movement will be in one direction, whereas ifthe ball element 127 is located between the motor shaft center line andthe opposite swivel ball element 124, the path of orbital movement willbe in the opposite direction. Thus, the invention provides a very simpleand convenient method of reversing the direction of orbital movement ofthe tool point without the necessity tor a reversible motor. 7.

In the position of the motion converting mechanism shown in FIG. 9, theeccentrically located swivel ball elements 123 and 124 are disposed oneabove the other in a vertical line and are located at the point ofmaximum forward displacement. It will be understood that when the gears116 and 117 have rotated 180 from the FIG. 9 position, the balls 123 and124 will again be disposed one above the other in vertical relation butat the point of maximum rearward displacement. Consequently, a back-.and-forth reciprocating movement is imparted to the socket member 129longitudinally of the casing. At the same time, as the gears 116 and 117rotate and 270 from the FIG. 9 position, the ball elements 122 and 123are disposed at opposite sides of'the gear axis (FIG. 10) to impart alateral component of movement in a plane transversely of the casing.

A further variation in this type of motion at the brush or tool pointmay be obtained by locating the swivel balls posed adjacent oppositesides of .the casing in a transverse seen that the center point of thepin 126 undergoes lateral back-and-ttonth movement in a straight linetransversely of the casing, and if the swivel ball 127 is located at thecenter point of the pin 126, a similar lateral backand-forth swingingmovement will be imparted to the brush or tool point. Actually, becauseof the pivoted fulcrum 138 the brush or tool point will have a slightarcuate path from side to side but the curvature is so minute that tothe eye it will appear as a straight line. Thus, by varying theeccentric locations of the swivel balls 12?: and 124 relative to thegears and to each other and by varying the location of the intermediateswivel ball 127 relative to the end balls 123 and 124-, a wide varietyof compound motions may be obtained at the brush or tool point.

FIGS. 12 and 13 illustrate a modification of the. arrangement shown inFIGS. 9-11 whereby oscillatory movement of the .tool socket and tool orbrush about its center line is obtained. The casing has upper and lowerpinion 154 on its shaft. A pair of plastic bevel gears 156 and 157 arejournaled in tubular bosses 158 and 159 extending from the casing walland are driven in opposite directions by the pinion 154 in the samemanner as in the previous embodiment of FIGS. 9 to 11. Power takeofffrom the gears 156 and 157 is again accomplished by means of a pair ofswivel balls 161 and 162 retained in swivel relation in correspondingsocket portions in the gears 156 and 157 and interconnected by a shaftsegment When the swivel ball element 127 is located on the With thisrelationship, it will'be 9 opening 166 therethrough for slidablyreceiving an elongated rearward extension 167 of a plastic socket member168.

The socket member 168 is cylindrical but has a rectangular opening 169for detachably receiving the shank of a brush or other tool member inthe manner previously described. The forward end of the casing has areduced diameter nose portion 171 with an opening 172 through which thesocket 168 extends. A cup-shaped flexible rubber seal 173 has a flangedend 174 retained in a circumferential groove 176 around the outside ofthe nose POD" tion 171, and the outer end of the seal 173 comprises anapertured wall or annular lip portion 177 in resilient engagement withan annular flange 173 extending integrally and outwardly from the socketmember 168. The socket member 168 and the opening 172 are provided withopposed circumferential grooves 179 and 181, respectively, with aplurality of ball bearing elements 182 disposed therebetween forrotatably supporting the socket member.

The motion imparted to the shaft segment 163 by means of the oppositelyrotating gears 156 and 157 is the same as in the embodiment of FIGS.9-11. However, in this instance, the socket member 168 is restrainedagainst longitudinal or axial movement by the ball elements 182 but isfree to rotate about its central longitudinal axis. Consequently, thesocket extension 167 remains in fixed position longitudinally of thecasing but the enlarged section 164 of the shaft segment slides back andforth between the full line and dotted line positions shown in FiG. 12as the gears 156 and 157 rotate. During rotation of the gears, the shaftsegment 163 also rocks from side to side transversely of the casingbetween the full line and dotted line inclined positions shown in FIG.13, and the keyed relationship between the shaft segment portion 164 andthe socket extension 167 causes the socket 168 to oscillate back andforth about its longitudinal axis through an arc of about 60.Accordingly, the tooth brush or other tool point undergoes the samerotary or oscillating movement.

A combination of the above-described oscillatory motion and straightaxial reciprocation can also be obtained with the structure of FIGS.12-13 by changing the support for socket 168 to permit both types ofmotion and at the same time rigidly connecting the socket extension 167and the segment 163 at the center point of the latter.

FIGS. 14-18 illustrate a further modification of the embodiment of FIGS.9-11 wherein the shiftable fulcrum for the socket is disposed rearwardlyof the gear axis and the connecting shaft segment rather than forwardlythereof. The casing has upper and lower halves 136 and 187 with a motor188 contained therein, a pinion 189 mounted on the motor shaft, and apair of plastic gears 191 and 192 journaled in tubular bosses extendingfrom the easing walls and driven in opposite directions by the pinion189. The power take-off swivel ball elements are designated at 193 and194 and are interconnected by a shaft segment 196 in the same manner aspreviously described.

An intermediate swivel ball element 197 is provided on the shaft segment196 and is retained in swivel relation in an elongated extension 193projecting rearwardly from a socket member 199 of rectangular externalshape. The socket extension 198 is fork shaped, as best seen in FIG. 16,and has a pair of laterally spaced arms 291 projecting rearwardly beyondthe axis of the ring gears 191 and 192. Each arm 261 extends between apair of upper and lower shoulders 202 and 203, respectively, provided inthe easing. The arms 201 are slotted, as at 264, and the shoulders 2G2and 203 are provided with corresponding grooves 206 with a pair of ballelements 207 disposed between each groove 206 and the confronting sideof the slot 204. Thus, a pair of movable fulcrums are providedrearwardly of the power take-off connection which accommodate bothback-and-forth reciprocating movement 1d and side-to-side pivotalmovement of the forked socket extension 198.

The nose end of the casing has a rectangular end opening 208 withoutwardly tapering side wall portions 209 (FIG. 16) to accommodateside-to-side swinging move ment of the socket member 199. Bearingsupport for the socket member 199 is provided by means of a pair of ballelements 211 seated in a pair of shallow circular recesses or sockets212 and rollably engaging the flat upper and lower surfaces of thesocket member 199. The circular recesses 212 are of relatively largediameter compared to the diameter of the balls 211 so as to accommodatecombined back-and-forth reciprocating and side-toside pivotal movementof the socket member 199.

As before, the socket member 199 has a square central opening 213 fordetachably receiving the shank of a tooth brush or other tool member.Likewise, the forward end of the socket member 199 has a groovedconstruction similar to that shown in FIG. 9 and is provided with aflexible rubber seal 214 extending between the grooved end of the socketmember and a similar groove in the nose of the casing.

As will be recognized, the location of the swivel ball element 197 alongthe shaft segment 1% is fixed in this instance so that the mechanismcannot be adjusted to provide either straight line or orbital movement,as may be desired. In the arrangement shown in FIGS. 14-18, the ballelement 197 is located between the center line of the motor drive shaftand the lower swivel ball 194 so as to transmit an orbital motion to thesocket member 199 in one direction. If the swivel ball 197 is locatedbetween the motor shaft center line and the upper swivel ball 193, andorbital path in the opposite direction is provided.

Although the invention has been described with particular reference tocertain specific structural embodiments thereof, it shouldbe understoodthat various alternatives and equivalent structures may be resorted toWithout departing from the scope of the invention as defined in theappended claims.

I claim;

1, Motion converting means for use in a power driven tool or the likecomprising, in combination, a rotatably driven gear element, a powertake-01f member having spaced end portions, means providing a swiveldriving connection between one of said end portions and said gearelement in eccentric relation to the axis of rotation of said gearelement, means axially spaced from said gear element providing a swivelsupport for the other of said end portions, means mounting said swivelsupport for movement of said other end portion relative to said axisduring rotation of said gear element, and movably supported meansconnected to said power take-01f member at an intermediate portionthereof between said end portions for receiving and transmitting theresultant motion of said powertake-olf member.

2. In a power driven device, the combination of an elongated housing, amotor in said housing having a drive shaft extending longitudinally ofsaid housing, a drive gear element mounted on said shaft, a socketmember movably supported at one end of said housing for mounting a toolor the like, and motion converting means interconnecting said drive gearelement and said socket member, said motion converting means comprisinga driven gear element meshed with said drive gear element and mountedfor rotation in said housing on an axis extending transversely of saiddrive shaft, a power take-off member having spaced end portions, meansproviding a swivel driving connection between one of said end portionsand said driven gear element in eccentric relation to said axis, meansaxially spaced from said driven gear element providing a swivel supportfor the other of said end portions, means mounting said swivel supportfor movement of said other end portion relative to said axis duringrotation of said driven gear element, and means connecting said socketmember to said power take-01f member at an intermediate portion thereofbetween said end portions.

3. In a power driven device, the combination of a motor driven shaft, apinion on said shaft, a gear element mounted for rotation on an axistransverse to said shaft and meshed with said pinion, a yoke memberhaving spaced arm portions and a central portion between said armportions, means providing a swivel driving connection between one ofsaid arm portions and said gear element in eccentric relation to saidaxis, means axially spaced from said gear element providing a movableswivel support for the other of said arm portions, and movably supportedmeans connected to said central portion of said yoke member forreceiving and transmitting the resultant motion of said yoke member.

4. In a power driven device, the combination of a motor driven shaft, apair of spaced coaxial gear elements mounted for rotation on an axistransverse to said shaft, means driven by said shaft for rotating saidgear elements in opposite directions, a power take-off member havingspaced end portions, means providing a swivel driving connection betweeneach of said end portions and one of said gear elements in eccentricrelation to said axis, and movably supported means connected to saidpower take-off member at an intermediate portion thereof between saidend portions for receiving and transmitting the resultant motion of saidpower take-off member.

5. In a power driven device including an elongated housing and a motormounted in the housing with its shaft extending longitudinally of thehousing, the combination of a pair of spaced coaxial gear elementsmounted for rotation on an axis transverse to said shaft, a pinion onsaid shaft meshed with said gear elementsfor rotating the latter inopposite directions, a yoke member having resilient spaced arm portionsdisposed adjacent said gear elements and a central portion between saidarm portions, means comprising a pair of ball elements in swivelengagement with said arm portions and the respective gear elements ineccentric relation to said axis for providing a driving connectionbetween said gear elements and said yoke member, a socket memberextending longitudinally of said housing and movably supported thereinfor mounting a tool or the like, and means connecting said socket memherto said central portion of said yoke member.

6. The structure of claim 5 further characterized in that said socketmember and said casing are provided with longitudinally shiftablefulcrum means for said socket member and'means for restraining saidsocket member against rotation about its axis, and said socket memberhas an axial end wall pivotally connected to said central portion ofsaid yokemember whereby to accommodate rocking of said yoke memberrelative to said socket member. I

7. The structure of claim 6 further characterized in that said end wallportion of said socket member and said central portion of said yokemember are provided with one pair of aligned apertures disposed on theaxis of said shaftand atleast one other pair of aligned apertures offsetfrom the axis of said shaft, and detachable pivot connecting means isprovided for selective engagement in either pair of apertures whereby toprovide either straight line reciprocating or orbital movement of saidsocket member.

8. In a power driven device including an elongated housing and a motormounted in the housing with its shaft extending longitudinally of thehousing, the combination of a gear element mounted for rotation on anaxis transverse to said shaft, a pinion on said shaft meshed with saidgear element for rotating the latter, a rigid support spaced axiallyfrom said gear element, a yoke member having resilient spaced armportions disposed adjacent said gear element and said support,respectively, and a central portion between said arm portions, meanscomprising a first ball element in swivel engagement between one of saidarm portions and said gear element in eccentric relation to said axisfor providing a driving connection therebetween, means comprisingconfronting guide portions on said support and. on the other of said armportions and a second ball element received therebetween for providing amovable swivel support for said other arm portion, said guide portionsbeing disposed so as to restrict movement of said second ball element ina straight path parallel to the axis of said shaft, a socket memberextending longitudinally of said housing andmovably supported thereinfor mounting a tool or the like, and means connecting said socket memberto said central portion of said yoke member.

9. The structure of claim 8 further characterized in that said socketmember and said casing are provided with longitudinally shiftablefulcrum means for said socket member and means for restraining saidsocket member against rotation about its axis, and said socket member.

has an axial end wall pivotally connected to said central portion ofsaid yoke member whereby to accommodate rocking of said yoke memberrelative to said socket member.

10. The structure of claim 9 further characterized in that said end wallportion of said socket member and said central. portion of said yokemember are provided with one pair of aligned apertures disposed in axialalignment with said=path and at least one other pair of alignedapertures offset from said path, and detachable pivot connecting meansis provided for selective engagement in either pair of apertures wherebyto provide either straight line reciprocating or orbital movement ofsaid socket member.

11. In a power driven device the combination of a motor driven shaft, apinion on said shaft, a pair of spaced coaxial gear elements mounted forrotation on an axis transverse to said shaft and meshed with said pinionfor rotating said gear elements in opposite directions, swivel meanscarried at the opposed faces of said gear elements in eccentric relationto said axis, an elongated connecting member extending between said gearelements with the opposite ends of said connecting member movablyengaging said swivel means, and movably supported means connected tosaid connecting member at an intermediate portion of the latter betweensaid ends for receiving and transmitting the resultant motion of saidconnecting member.

12.. The structure of claim 11 further characterized in that said swivelmeans comprises a pair of ball elements having a swivel mounting in saidgear elements and said connecting member comprises a pin with itsopposite ends slidably received in said ball elements.

13. The structure of claim 12 further characterized in that said movablysupported means comprises a socket member connected to said pinintermediate the ends of the latter by means slidably adjustablelengthwise of the pin and mounted in swivel relation to said socketmember.

14. The structure of claim 12 further characterized in that said pin hasan intermediate ball element slidably mounted thereon intermediate saidpair of ball elements and said movably supported means comprises asocket member having an extension with said intermediate ball elementmounted in swivel relation in said extension.

15. The structure of claim 14 further characterized by the provision ofa tubular fulcrum support for slidably, receiving said socket member andrestraining the same against rotation about its axis, means pivotallymounting the provision of a pair of pivots extending from opposite sidesof said fulcrum support, means supporting said pivots for rotary andaxial sliding movement, spring means 13 at one side of said fulcrumsupport for urging said fulcrum support in one direction, and threadedadjustm nt means at the opposite side of said fulcrum support forregulating the position of said fulcrum support and said socket member.

17. The structure of claim 12 further characterized in that said movablysupported means comprises a socket member supported for rotaryoscillation about its axis With means providing a non-rotatable butlongitudinally slidahle connection between said socket member and anintermediate portion of said pin.

18. The structure of claim 17 further characterized in that said pin hasan enlarged intermediate portion With a non-circular aperture and saidsocket member has an elongated extension of non-circular cross-sectionslidably disposed through said aperture.

19. The structure of claim 12 further characterized in that said movablysupported means comprises a socket member supported for orb a1 movementforwardly of said pin, a rearward extension on said socket member havinga swivel connection with an intermediate portion of said pin and a pairof yoke arms projecting rearwardly beyond said pin, and means coactingWith said yoke arms and providing a pair of oppositely disposedshiftable fulcrum supports for said yoke arms.

20. The structure of claim 19 further characterized in that saidlast-named means comprises guide portions confronting said yoke arms andball means interposed thereoetween.

References Cited in the file of this patent UNITED STATES PATENTS1,956,281 Granberg Apr. 24, 1934 2,372,731 Nalbach et a1 Apr. 3, 19452,648,787 Smithson Aug. 11, 1953 2,657,321 Smithson Oct. 27, 1953

1. MOTION CONVERTING MEANS FOR USE IN A POWER DRIVEN TOOL OR THE LIKECOMPRISING, IN COMBINATION, A ROTATABLY DRIVEN GEAR ELEMENT, A POWERTAKE-OFF MEMBER HAVING SPACED END PORTIONS, MEANS PROVIDING A SWIVELDRIVING CONNECTION BETWEEN ONE OF SAID END PORTIONS AND SAID GEARELEMENT IN ECCENTRIC RELATION TO THE AXIS OF ROTATION OF SAID GEARELEMENT, MEANS AXIALLY SPACED FROM SAID GEAR ELEMENT PROVIDING A SWIVELSUPPORT FOR THE OTHER OF SAID END PORTIONS, MEANS MOUNTING SAID SWIVELSUPPORT FOR MOVEMENT OF SAID OTHER END PORTION RELATIVE TO SAID AXISDURING ROTATION OF SAID GEAR ELEMENT, AND MOVABLY SUPPORTED MEANSCONNECTED TO SAID POWER TAKE-OFF MEMBER AT AN INTERMEDIATE PORTIONTHEREOF BETWEEN SAID END PORTIONS FOR RECEIVING AND TRANSMITTING THERESULTANT MOTION OF SAID POWER TAKE-OFF MEMBER.